Dario Alfè, David Price and Mike Gillian of University College London used a Cray T3E supercomputer to calculate that the melting point of iron was 6700 Kelvin, plus or minus 600 Kelvin, at the pressure of the inner core boundary. The inner and outer cores store tremendous amounts of energy as heat. The transfer and […]
Read article: New hope for physics education
Physics teaching is being transformed in the UK and the Institute of Physics is leading the way with a forward-looking initiative designed to revitalize the subject and attract more students
Towards the end of the last century many physicists feared that their work was done and that the end of physics was in sight. In 1894, for instance, Albert Michelson said that “it seems probable that most of the grand underlying principles [of physical science] have been firmly established”. Of course, the discovery of X-rays, […]
Read article: Supersymmetry stands the test
An international team of nuclear physicists has found strong evidence for the existence of nuclear supersymmetry, a theory that relates bosons, which have integer values of spin, and fermions, with half-integer values of spin. The researchers from Germany, Switzerland and the US obtained the results in a series of complex experiments at the Paul Scherrer […]
Superconductivity happens when the charge carriers overcome their mutual repulsion and bind together into Cooper pairs. In low-temperature superconductors phonons – quantized vibrations of the crystal lattice – are responsible for this pairing. Jules Carbotte from McMaster University in Canada, Ewald Schachinger from the Technical University of Graz in Austria, and Dimitri Basov from the […]
Read article: Chandra delights astronomers
The image of G21.5-0.9, a supernova remnant which is 16,000 light years from Earth, shows a bright central source (the neutron star) with bright nebula and surrounded by a much larger diffuse cloud. The fluffy appearance of the central nebula is thought to be due to magnetic field lines which constrain the motions of the […]
Who do you think will win? Will the prize be awarded for the discovery of the top quark, Bose-Einstein condensation, the gluon, the semiconductor laser, the anisotropy in the cosmic background radiation, the geometric phase, experiments on Bell’s inequalities, neutrino oscillations, giant magnetoresistance, quasicrystals, molecular beam epitaxy, quantum chromodynamics or something else? Please send us […]
Most semiconductor lasers emit light from the edge of the active laser region. However, in the VSCEL geometry light is emitted from the top of the device. This can reduce the threshold current needed to achieve laser action and can improve the optical quality of the output beam. The new device consists of an indium […]
The first evidence for the accelerating universe came from observations of distant supernovae. However, the data were also consistent with an open universe – a universe that would expand forever because the total energy density was less than the so-called critical density – with a low mass density and no cosmological constant. The energy density […]
Brian DeMarco and Deborah Jin used a pair of magneto-optical traps to confine about 700000 atoms of potassium-40 at temperatures below 300 nanokelvin. This is about half of the degeneracy temperature for a gas of fermions. At these temperatures the occupation of the lowest quantum states increases from around zero to about 60%. The quantum […]
